Department of Plant Biology, Carnegie Institution of Washington, Stanford, California 94305.
Plant Physiol. 1981 May;67(5):1042-6. doi: 10.1104/pp.67.5.1042.
A membrane fraction which contains a blue light-sensitive flavin-cytochrome complex (Brain et al. 1977 Plant Physiol 59:948) has been partially purified by sucrose and Renografin gradient centrifugations. Assays for marker enzymes show that this membrane fraction is distinct from endoplasmic reticulum, golgi, and mitochondria. This membrane fraction co-sedimented with glucan synthetase II activity, a proposed marker for plasma membrane in higher plants. The purified membrane fraction shows virtually identical light minus dark and dithionite reduced minus oxidized difference spectra with difference bands near 427 and 557 nanometers, suggesting that contamination by other cytochrome-containing membrane fractions is not significant. The photoactivity can be completely solubilized by 0.1% Triton X-100, leaving the bulk of the membrane undissolved. The kinetics for cytochrome photoreduction are not significantly affected by solubilization, indicating that both flavin and cytochrome could be associated with the same protein moiety.
通过蔗糖和雷尼酸铬梯度离心,已部分纯化出含有蓝光敏感黄素-细胞色素复合物的膜级分(Brain 等人,1977 年,植物生理学 59:948)。标记酶的测定表明,该膜级分与内质网、高尔基体和线粒体不同。该膜级分与葡聚糖合成酶 II 活性共沉淀,葡聚糖合成酶 II 活性是高等植物质膜的一个建议标记物。纯化的膜级分显示出几乎相同的光暗和连二亚硫酸钠还原氧化差光谱,具有近 427 和 557 纳米的差带,表明受其他含细胞色素的膜级分污染不显著。0.1%Triton X-100 可完全溶解光活性,留下大部分膜不溶解。细胞色素光还原动力学不受溶解的显著影响,表明黄素和细胞色素都可能与同一蛋白部分相关。